Upgrade Hydra-Z with simply playing a special firmware update ".wav" file. Hydra-z will detect and load it automatically. It is very handy feature.
When Hydra-Z start firmware update, the PCM/DSD LED will start flashing alternatively. Once upgrade complete, both LEDs will be on. And just reboot the Hydra-Z, the upgrade would be completed.
So make sure that you have a bit perfect player and do NOT interrupt it once the upgrade is started.
I found this version 1.01 improve the sonic performance.